Deck 3: Chemical Basis of Life

Question 1

The type of reaction in which substances are combined to form more complex substances is called a(n) _____ reaction.

A) reversible
B) exchange
C) synthesis
D) decomposition

Answer 1

C

Question 2

An isotope of an element contains different numbers of ____ from other atoms of the same element.

A) electrons
B) protons
C) neutrons
D) both protons and neutrons

Answer 2

C

Question 3

Which of the following bonds are the weakest?

A) Ionic
B) Hydrogen
C) Electrovalent
D) Covalent

Answer 3

B

Question 4

The most abundant and important compound(s) in the body is(are):

A) air.
B) water.
C) proteins.
D) nucleic acids.

Question 5

The process of the digestion of food is an example of which type of reaction?

A) Synthesis
B) Decomposition
C) Exchange
D) Reversible

Question 6

A negatively charged subatomic particle that moves around the nucleus is a(n):

A) orbital.
B) proton.
C) neutron.
D) electron.

Question 7

When atoms combine, they may gain, lose, or share:

A) electrons.
B) protons.
C) neutrons.
D) nuclei.

Question 8

Carbon has an atomic number of 6. The number of electrons found in the first shell is:

A) two.
B) four.
C) six.
D) eight.

Question 9

An example of an element would be:

A) Ne.
B) CO₂.
C) C₆H₁₂O₆.
D) H₂O.

Question 10

The atomic number of carbon is 6. How many unpaired electrons are in its outer shell?

A) Two
B) Three
C) Four
D) Five

Question 11

In the presence of a base, red litmus paper will:

A) stay red.
B) turn blue.
C) turn green.
D) turn yellow.

Question 12

An ionic bond is formed by:

A) two or more positive ions combining.
B) two or more negative ions combining.
C) a positive and a negative ion attracting each other.
D) sharing of a pair of electrons.

Question 13

Acids:

A) are proton donors.
B) taste sour.
C) release hydrogen ions in an aqueous solution.
D) All of the above are true of acids.

Question 14

Which of the following elements is least likely to combine with another element?

A) Hydrogen
B) Helium
C) Oxygen
D) Carbon

Question 15

Substances that accept hydrogen ions are called:

A) acids.
B) bases.
C) buffers.
D) salts.

Question 16

The kind of element is determined by the number of:

A) protons.
B) neutrons.
C) mesotrons.
D) electrons.

Question 17

A solution that contains a greater concentration of hydroxide ions (OH-) than hydrogen ions (H⁺) is a(n) _____ solution.

A) acidic
B) alkaline (basic)
C) neutral
D) Not enough information is given to determine the character of the solution.

Question 18

The hydrogen isotope tritium consists of:

A) one proton.
B) one proton and one neutron.
C) two protons and one neutron.
D) one proton and two neutrons.

Question 19

Atomic weight is determined by the number of:

A) protons and electrons.
B) neutrons and electrons.
C) neutrons, protons, and electrons.
D) protons and neutrons.

Question 20

Which of the following represents a trace element in the body?

A) Sulfur
B) Chlorine
C) Iron
D) Phosphorus

Question 21

The type of chemical reaction most likely to require energy is a(n) _____ reaction.

A) synthesis
B) decomposition
C) exchange
D) All of the above reactions are equally likely to require energy.

Question 22

Which of the following is not one of the major groups of organic substances in the human body?

A) Proteins
B) Salts
C) Lipids
D) Nucleic acids

Question 23

The elements carbon, hydrogen, oxygen, and nitrogen make up which percentage of the human body?

A) 50%
B) 69%
C) 78%
D) 96%

Question 24

Chemical bonds formed by the sharing of electrons are called:

A) ionic.
B) covalent.
C) hydrogen.
D) isotopic.

Question 25

Ionic bonds are chemical bonds formed by the:

A) sharing of electrons between molecules.
B) donation of protons from one atom to another.
C) transfer of electrons from one atom to another.
D) acceptance of neutrons from one atom by another.

Question 26

Which of the following is not one of the major elements present in the human body?

A) Oxygen
B) Zinc
C) Carbon
D) Potassium

Question 27

The total number of electrons in a neutral atom equals the number of:

A) neutrons orbiting the atom.
B) protons plus the number of neutrons in its nucleus.
C) protons in its nucleus.
D) ions in its nucleus.

Question 28

An atom can be described as chemically inert if its outermost electron shell contains _____ electrons.

A) eight
B) nine
C) two
D) Both A and C are correct.

Question 29

AB + C→AD + CB is an example of a(n) _____ reaction.

A) synthesis
B) exchange
C) decomposition
D) reversible

Question 30

Which of the following is not a subatomic particle?

A) Proton
B) Electron
C) Radon
D) Neutron

Question 31

The element oxygen has an atomic number of 8, which means it contains:

A) four protons and four neutrons.
B) eight protons.
C) eight neutrons.
D) four protons and four electrons.

Question 32

The formation of sucrose involves the removal of a molecule of water. This is called:

A) hydrolysis.
B) oxidation.
C) decomposition.
D) dehydration synthesis.

Question 33

Which of the following represents properties of water?

A) High specific heat
B) High heat of vaporization
C) Strong polarity
D) All of the above

Question 34

Which subatomic particles carry a charge?

A) Protons and neutrons
B) Neutrons and electrons
C) Protons and electrons
D) Neutrons only

Question 35

The study of metabolism includes examination of:

A) catabolism.
B) anabolism.
C) ATP requirements.
D) all of the above.

Question 36

An example of a catabolic process is:

A) hydrolysis.
B) dehydration synthesis.
C) formation of a peptide bond.
D) both B and C.

Question 37

The approximate pH of gastric fluid is:

A) 10.
B) 8.
C) 4.
D) 2.

Question 38

For sodium to transform from a neutral atom to a positive ion, it must:

A) gain an electron.
B) gain a proton.
C) lose an electron.
D) lose a proton.

Question 39

All of the following substances are organic except:

A) lipids.
B) electrolytes.
C) carbohydrates.
D) proteins.

Question 40

Approximately what percentage of body weight is water?

A) 40%
B) 50%
C) 60%
D) 70%

Question 41

When your body is building larger and more complex chemical molecules from smaller subunits, what is occurring?

A) Anabolic reactions that expend energy
B) Anabolic reactions that require energy
C) Catabolic reactions that expend energy
D) Catabolic reactions that require energy

Question 42

Hydrolysis _____ a water molecule.

A) joins compounds by removing
B) breaks down compounds by removing
C) joins compounds by adding
D) breaks down compounds by adding

Question 43

If an atom with a total of nine electrons were to ionically bond with an atom with a total of three electrons, what would occur?

A) The atom with nine electrons would share one of its electrons with the other atom.
B) The atom with nine electrons would lose one of its electrons, and the atom with three electrons would accept it.
C) The atom with nine electrons would accept one of the electrons from the atom with three electrons.
D) The atom with three electrons would share one of its electrons with the other atom.

Question 44

A molecule that is polar:

A) can form a hydrogen bond.
B) must be ionic.
C) has an unequal charge.
D) is both A and C.

Question 45

When sodium (Na) gives up an electron to chlorine, the result is the formation of a sodium ion (Na⁺) with a positive charge. This happens because there is then one more _____ than _____.

A) proton; electron
B) electron; proton
C) proton; neutron
D) electron; neutron

Question 46

The reaction between hydrogen and oxygen needed to form water is an example of a:

A) hydrogen bond.
B) synthesis reaction.
C) decomposition reaction.
D) None of the above is correct.

Question 47

As the concentration of hydroxide ions (OH-) increases, the:

A) solution becomes more basic.
B) solution becomes more acidic.
C) pH rises.
D) Both A and C are correct.

Question 48

A magnesium atom has an atomic number of 12, an atomic mass of 25, and a +2 charge. This atom would contain _____ protons, _____ neutrons, and _____ electrons.

A) 12; 25; 2
B) 12; 13; 14
C) 12; 13; 10
D) Not enough information is given to answer the question.

Question 49

A weak acid:

A) dissociates very little in solution.
B) dissociates almost completely in solution.
C) will cause the pH of the solution to rise above 7.
D) does both B and C.

Question 50

Which of the following is not true of all isotopes of oxygen?

A) They can all react with two hydrogen atoms to form water.
B) They have the same number of protons.
C) They have the same atomic mass.
D) All of the above are true of isotopes of oxygen.

Question 51

The carbon-containing molecules formed by living things are often called:

A) buffers.
B) inorganic molecules.
C) organic molecules.
D) salts.

Question 52

As the concentration of hydrogen ions (H⁺) increases, the:

A) solution becomes more basic.
B) solution becomes more acidic.
C) pH rises.
D) Both A and C are correct.

Question 53

If the pH of a person's blood is 7.4, it would be described as:

A) strongly acidic.
B) neutral.
C) slightly acidic.
D) slightly alkaline.

Question 54

The octet rule refers to the:

A) stability of the nucleus when the protons are in a multiple of eight.
B) stability of the atom when there are eight electrons in the outermost energy level.
C) stable configuration of the nucleus when there are eight more neutrons than protons.
D) principle that one atom can combine with a maximum of eight other atoms.

Question 55

Salts:

A) can form as the result of a chemical reaction between acids and bases.
B) are electrolytes.
C) will form crystals if the water is removed.
D) All of the above are correct.

Question 56

The term that is used to describe all of the chemical reactions that occur in body cells is:

A) catabolism.
B) metabolism.
C) synthesis.
D) anabolism.

Question 57

The type of reaction most likely to release energy is a(n) _____ reaction.

A) synthesis
B) decomposition
C) exchange
D) All of the above reactions are equally likely to release energy.

Question 58

A strong acid:

A) holds on strongly to its hydrogen atoms, releasing very few in solution.
B) would cause a drop in the pH of a solution.
C) would cause a rise in the pH of a solution.
D) is both A and C.

Question 59

Electrolytes are:

A) organic compounds.
B) called cations if they have a negative charge.
C) called cations if they have a positive charge.
D) both A and B.

Question 60

Hydrogen can form only when the hydrogen atom is covalently bonded to:

A) an oxygen atom.
B) a nitrogen atom.
C) a fluorine.
D) any of the above.

Question 61

The digestion of food is an example of a decomposition reaction.

Question 62

Radioactivity can cause an atom of one element to change to that of another element.

Question 63

An isotope of an element contains the same number of neutrons but different numbers of protons.

Question 64

Water acts as a very effective solvent.

Question 65

Which type of radiation consists of an electron that is released by the nucleus of an atom?

A) Alpha
B) Beta
C) Delta
D) Gamma

Question 66

The number and arrangement of electrons orbiting in an atom's outer shell determine its chemical activity.

Question 67

An atom is chemically inert if its outermost shell has two pairs of electrons.

Question 68

The positively charged electrons are found in clouds outside the nucleus of an atom.

Question 69

A + B « AB is an example of a(n) _____ reaction.

A) decomposition
B) reversible
C) exchange
D) Both A and B are correct.

Question 70

Electrolytes include acids, bases, and salts.

Question 71

Radiation results from the breaking apart of the nucleus of an atom.

Question 72

Which type of radiation consists of two protons and two neutrons?

A) Alpha
B) Beta
C) Delta
D) Gamma

Question 73

The octet rule refers to the:

A) stability of the nucleus when the protons are in a multiple of eight.
B) stability of the atom when there are eight electrons in the outermost energy level.
C) stable configuration of the nucleus when there are eight more neutrons than protons.
D) principle that one atom can combine with a maximum of eight other atoms.

Question 74

A substance that resists changes in pH when acids or bases are added is called a buffer.

Question 75

The chemical reaction of an acid with a base will produce a salt and water.

Question 76

Electrovalent and ionic bonds are the same.

Question 77

Two shared pairs of electrons represent a single covalent bond.

Question 78

The number of protons in the nucleus of an atom determines its atomic mass.

Question 79

Gamma radiation has less mass than alpha or beta radiation.

Question 80

Which type of radiation consists of electromagnetic radiation, a form of light energy?

A) Alpha
B) Beta
C) Delta
D) Gamma